Electric heater.



E. THOMSON. ELECTRIC HEATER. 4 APPLIOATION FILED JUNE 17,1907.

-' Patented Oct.27, 1908.

NTU R:

ELI H u THE! MEI] N,

WITN 53:15:: m Qayh w UNITED STATES PATENT onero s.

ELIHU THOMSON, OF SWAMPSOOTT, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

nnncrarc HEATER.

Specification of Letters Patent.

Ilatenlied Oct. 27, 1908.

Application filed June 17,1907. carer-n5. 379,362.

.To all whom it mag concern: I

Be it known that I, ELIHU TiioMsoN, a citizen of the United States, residing at Swampseott, in the county of Essex, State of I ers, of'whicht This invention relates 'to electric heaters.

Massachusetts, have invented certain new and useful Improvements in Electr c Heate following is a specification.

Sand has for. its object the provision of a device of this character whereby the energy of an'e'lectric current will be transformed into heat in a safe and efiicient manner;

"In carrying out my invention I utlhze as I the medium of distribution of the heat energy, a fluid, such as water, which. will be vaporized. Only' a smallamount of fluid is used however, and the energy is not transformed by circulation of the fluid but by the generation of vapor within a sealed or airtight receptacle. A limited quant ty of fluid is vaporized and then enters an extended iairor the condensing surface is calculated to pressure.

such that the temperature will never get be-- be in excess of that which would be required to dissipate the heat produced by the electric unit at boiling temperature or at a given In other words, the surface will be {end the boiling point of the fluid, or it may e so arranged that aslight pressure may be enerated within the condensing s ace, but %he pressure will never rise above t 1e predetermined point. The amount of waterpresent at any time will be so small'that there will'be no danger of injury by freezing or the like. the radiating surface is thus obtained in a A practically perfect distribution of very safe and simple manner.

In the accompanying drawing 1 have shown my invention embodied in a specific structure which it should be understood is merely for purposes ofillustration.

1n the drawings, Figure l is a side eleva-.

tion of an eleetric heater embodying my in vention, the cas ng being partly broken away; Figs-Q an elevation of the same likewise partly broken awa Fig. 3 is a sectional elevation of a slightly modified form of my invention; Fig. 4 is an end elevation of" the same partly in section; and Fig. 5 is a transverse section thereof. a

Referring to drawings (Figs. 1 and 2) 10 is a sheet metal corrugated casin entirely inclosed and sealed Watentight. he casing is somewhat contracted in ion th at the bottom and is provided with an e ectric heating unit 11 extending longitudinally and corn trally of the casing. lhe unit fits into a sleeve 12 which is preferably sup ortedonly at the ends so as to leave an-annu a1- space 13 for the fluid 14 which may be water, if dcsired The sleeve is united to the casingby a. tight joint to prevent the escape of liquid and vapor. By this arrangement thefiuid is in heat-conductive relation to the unit, and can quickly be brought up 'to' the boiling temperature. When the water boils, steam will rise into the condensing space 15 and will be condensed and run back into the bottom of the casing. The radiating surface is large enough to condense all ofthe vapor produced by the heating unit at-boilin temperature of the water so that practica ly m ressure will be generated within'the casing. if desired, however, the radiating surface may be so proportioned to the supplyof heat that a predetermined pressure may exist in thecasing. As the vapor rises it is condensed and almost a perfect distribution of the heat is made throughout the casing, If desired, the air in'the casing may be exhausted or rarefied and the apparatus'may be worked with the water below its normal boiling point. In this case the water may be vaporized at almost any tem erature above the freezing point when the istribu--- tion of heat will be perfect and in reportion to the heat energy absorbed )y the electric resistance. The small amount of water makes an accident due to excessive pressure or the like impossible. Figs. 3 to 5 show a similar arrangement,

the only difference being the specific construetion through which the fluid is heated by the electric unit. In this case a plug of good conducting metal 16 such as copper or the like, forms the bottom of the casing and the heatin unit 1-? is inserted centrally. thereof. 1e waterlies in a shallow, groove iorined in the upper'part of this piece and N therefore will beavery readily vaporized.

Either of these ty es is very convenient for small units to be rung on the wall in such .stand u on the legs 19.

It Wll be understood, of course, that I have, in accordance with the patent statutes, shown and described specific means whereby the invention may be carried out, but it should be further understood that other means will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. An electric heater comprising an airtight rece tacle containing a uantity of fluid, an e ectric heating device or va oriz ing said fluid, and radiating walls inc osing an extended space Communicating with said fluid adapted to condense the vapor, the condensing' space being larger than the fluid space.

2. An electric heater comprising an air tight rece tacle containing a quantity of fluid, an e ectric heating device in heat-com ductive relation to said fluid, and radiating walls formin a space communicatin with said fluid an arranged to condense the vapor, the condensing space being several times as large as the fluid space.

3. An electric heater comprisin an airtight receptacle having heat radiating walls,

' Witnesses:

a quantity of fluid in said receptacle and occupying a small portion of the space thereof, and an electric heating device in conductive relation to said fluid arranged to vaporize the same.

4. An electric heater comprising an airtight receptacle containing a quantity of fluid and having a condensing space several times larger than the fluid s ace above and in communication with Siti( fluid, and an electric heating device for vaporizing said fluid.

5. An electric heater comprising a fluid container, an electric heating device in heatconductive relation thereto, and a corrugated casing forming a condensing space communicating with the fluid.

6. An electric heater comprising an airtight receptacle containing a quantity of fluid, means for vaporizing said fluid, radiating walls forming an extended space communicating with said fluid, said walls having a radiating surface in excess of that required to dissipate the heat produced at substantially the boiling temperature of the fluid.

-7. An electric heater comprising a closed container, a vaporlzable flui therein and a heating unit for the fluld, said container hav ing an internal capacity suflicient to contain" the completely vaporized fluid at approximately atmosphere pressure.

In witness whereof, I have hereunto set my hand this twelfth day of June, 1907.

ELIHU THOMSON.

JOHN A. MeMANUs, Jr.,. PHILIP F. HARRINGTON. 

